Drawing-board



'L. WLMOORE.

DRAWING BOARD.

APPLICATION FILED MAR. 17, 19 9.

5 Patented Oct. 25,, 1921.

2 SHEETSSHEET I.

anvewi oz L. W. MOORE.

DRAWING BOARD.

APPLICAT4ION FILED MAR. 17. 1919.

1,395,200. a ted 00th 25, 1921.

2 SHEETS-SHEET 2.

' UNITED STATES;

PATENT OFF-ICE.

LEON w. moons, or sm'ra'mm, cmroimm DRAWING-BOARD.

To all whom it may concern:

Be it known that-I, LEON W. Moons, a

citizen of the United States,residing at Santa Maria, in the county ofSanta Barbara, State of California, have invented certain, new anduseful Improvements in Drawing-Boards;

and I do hereby declare the following to be a full, clear, and exactdescription of the in ,vention such as will enable others skilled in theart to which it appertains to makeand use the same. v

The invention relates to a drawing board and more particularly to theclass of drafting boards adapted for ofiice and field use.

The primary object of the invention is, the provision of a draftingboard of this character, wherein a piece of work can be laid out withaccuracy so that the correct angles can be had and the propermeasurements determined with despatch, and in event of an error the samecan be detected without requiring the assistance of a small protractorwhen the board is being used for small office work or in the field,which in the latter use will serve as an ordinary transit.

Another object of the invention is, the pro vision of a drawing board ofthis character,

wherein the construction thereof is novel in form to assure intricatecharacter work to be plotted either in an oflice or in a field so thatany desired angle may 'behad with accuracy and the degree dispositionthereof determined with despatch.

A further object of the invention is, the provision of a board 0 thischaracter which is extremely simple in construction, readily and easilyoperated, thoroughly eflicient in its purpose, strong,-durable andinexpensive to manufacture.

With these and other ob'ects in view, the invention consists in theeatures of construction, combination and. arrangement of partsas will behereinafter fully described, illustrated in the accompanying drawing andpointed out in the claims hereunto appended.

In the accompanying drawing:

F i re 1, is a top plan view of a drawing boar constructed in accordancewith the invention, the board being shown by full lines and by dottedlines .is indicated a piece of work and a T-square for the drafting ofan angle line in the use of the board.

Fig. 2, is an edge-elevation thereof.

Fig. 3, is a sectional. view on the line 33 of Fig. 1. Y

Specification of Letters Patent. 'Patented Oct, 25, 1921,

Application filed March 17, 1919. Serial No. 283,111. I

Fig. 4, a plan looking oppositely from v Fi 1. v i Fig. 5, isafragmentaryenlarged vertical sectional v1ew showing in detail one ofthe countersunk 1 nuts. I

Referring to the drawingv in detail, A,

designates generally the drawing board which comprises the rectangularbody sect1on 10 preferably. made from wood and'of the requlred size inlength, width and thickness, which is formed with a circular rabbetedcentral opening 11 ,in which is fitted the circular board section 12formed with a rabbeted marginal edge 13 to overlap the rabbeted edge ofthe opening 11 in the section 10, so that the opposite faces of thesection 10 will be flush with the opposite faces of the circular boardsection 12.

Mounted between the rabbeted edges of the sections 10 and 12 atdesirable intervals are cups bearing balls 14 which permit smooth andeasy movements of the sections with respect to each other.Concentrically of the center opening 11 on the section 10 are suitablymarked or otherwise indicated on each face thereof independent scales 15graduated into degrees of a circle, namely On the section 12 is printedor otherwise marked a north indicator 17 while at 18 is printed ormarked a south indicator to coso as to frictionallyfour points thereofequally distant from each other are countersinks or recesses 21 in whichare fitted nuts 22 forming threaded sockets for the detachable mountingof the board A upon a tripod for the use-0f said board in a field, therecesses 21 being normally closed through the medium of removable plugs30 when the said board is adapted for office use.

Suitably counterseated within grooves in the face of the section 10which is opposite to that face of the section 12 in which the recesses21 are formed and near the left hand ends of the north and south edgesthereof are hinged folding sights 25 and 24 respectively, normallylowered to inactive position, but adapted to be raised at right anglesto the face of the board A when it is used for field work.

To operate the board for ofiice workthe side thereof in which therecesses 21 are formed is uppermost. A piece of work as indicated by Bin Fig. 1 of the drawing is tacked or otherwise enga ed on the board.

It is to be noted that t e left hand'edge portion of the section 12 isdesignated 'as east, while the right hand edge portion is designated aswest.

In order to plot a line with the course of north 20 west, the. section12 is revolved to the right into the northwest quadrant of the circleuntil the indicator 17 coincides with the 20 mark on the graduated scale15 on the section 10 of the board which disposes the piece of work Bangularly as indicated by the dotted lines in Fig. 1, of the drawing.

A T-square as indicated by C in Fig. 1 is operated back and forth alongthe south edge of section 10 with the blade of the T-square extended atall times north and south; and as shown in Fig. 1, by positioning theT-square at a bearing of 20 west from any point on the section 12, the

desired line can be indicated. It will be apparent that any bearing inany direction may be plotted.

To operate the board in the field, the same may be supported upon atripod of any approvedtype by engaging the tripod in the sockets 22after removing the plugs 30, the board being reversed from the positionshown in Fig. 1 for this purpose. The center of the board must be at thecenter of the tripod when the said tripod is accurately set,

. thereafter the folded sights 24 and 25 are raisedwith one of the samepositioned at the north end and the'6ther at the south end. The sectionl0'may now berevolveditbout the section 12 which is stationary. The

cators are set at zero and the rear sight is taken the same as that withthe transit on any object ahead and by the use of the T- square Coperating at the south edge of the section 10 a line can be drawn froman desired point and distances scaled.

From the foregoing it is thought that the construction and manner of useof the drawing board will be clearly understood and therefore a moreextended explanation has been omitted; i

What is claimed is:

1. A drawing board of the character described, comprising a straightedge section having a circular opening, a center section shaped "to fitthe opening and revoluble: therewithin, said straight edge sectionhaving degree marks of a circle thereon around its opening and saidcenter section being provided with indicators coacting with said marks,and foldable sights carried by one face of the straight edge section foralinement in with diametrically opposite points of the same.

3. A drawing board of the character described, comprising a squaresection having a circular opening rabbeted around its edge, a roundcenter section fitted to the opening and having a rabbeted edgecooperating therewith, antifriction means interposed between therabbets, said square section having degree marks of a circle thereon andsaid center section being provided with an indicator coactin therewith,and foldable sights carried by t e square section Within two grooves inone face thereof adjacent diametrically opposite points of the same.

In testimony whereof, I aflix my signature.

LEON W. MOORE.

